Cache exception

Did anyone encounter this error?

```
   File "/usr/local/lib/python3.8/dist-packages/ua_parser/user_agent_parser.py", line 250, in Parse
     entry = _lookup(user_agent_string, jsParseBits)
   File "/usr/local/lib/python3.8/dist-packages/ua_parser/user_agent_parser.py", line 224, in _lookup
     entry = _PARSE_CACHE.get(key)
   TypeError: unhashable type: 'list'
```